Printing unit having at least two lateral frame parts the distance of which can be changed relative to each other in a horizontal direction

Abstract

A printing unit has at least two lateral frame parts. The distance between which can be changed, relative to each other, in a horizontal direction. Each frame part receives a printing group or parts of such a printing group. At least one of the lateral frame parts is displaceably supported for movement between a functional position, in which the lateral frame parts meet and are affixed relative to one another, and an open position in which the lateral frame parts are positioned at a distance from each other. The support of the at least one movable lateral frame part has at least one sliding surface which is made using a composite plastic that is composed of multiple materials.

1. A printing unit comprising:
 at least a first side frame part and a second side frame part, a spacing distance between said first side frame part and said second side frame part, relative to each other, being adjustable in a horizontal direction of displacement by movement of at least one of said first side frame part and said second side frame part, relative to the other of said at least first side frame part and said second side frame part in said horizontal direction of displacement; 
 at least one of a printing couple and a part of a printing couple accommodated on each of said first and second side frame parts; 
 a mounting supporting said movable one of said at least first and second side frame parts for movement in said direction of displacement between a closed functional position, in which said first and second side frame parts are moved together and are fixed relative to each other, and an open position in which said at least first and second side frame parts are spaced from one another in said direction of displacement; 
 at least one sliding surface in said mounting and supporting said movable one of said at least first and second side frame parts, said at least one sliding surface being a composite plastic comprised of multiple materials including a thermoplastic polyester component; and 
 a plurality of depressions in said at least one sliding surface, said plurality of depressions being capable of holding soil. 
 
     
     
       2. The printing unit of  claim 1 , further including a sliding block including said at least one sliding surface made of said composite plastic. 
     
     
       3. The printing unit of  claim 2 , wherein said sliding block includes a sliding block base and a sliding layer attached to said sliding block base. 
     
     
       4. The printing unit of  claim 3 , said sliding layer is made of plastic. 
     
     
       5. The printing unit of  claim 1 , wherein said composite plastic has a friction coefficient between 0.02 and 0.40 with a surface pressure of between 1.0 and 4.0 N/mm 2  and a temperature of 25° C. 
     
     
       6. The printing unit of  claim 5 , wherein said composite plastic has a friction coefficient between 0.04 and 0.30 with a surface pressure of between 0.5 and 4.0 N/mm 2  and a temperature of 25° C. 
     
     
       7. The printing unit of  claim 6 , wherein said composite plastic has a friction coefficient between 0.06 and 0.12 with a surface pressure of between 0.3 and 4.7 N/mm 2  and a temperature of 25° C. 
     
     
       8. The printing unit of  claim 1 , wherein said composite plastic has a tensile strength of between 30 and 100 N/mm 2 . 
     
     
       9. The printing unit of  claim 1 , wherein said composite plastic has a wear factor at 20° C. of less than 0.2 mm/100 Km. 
     
     
       10. The printing unit of  claim 9 , wherein said composite plastic has a wear factor at 20° C. of less than 0.1 mm/100 Km. 
     
     
       11. The printing unit of  claim 9 , wherein said composite plastic has a wear factor at 20° C. of less than 0.05 mm/100 Km. 
     
     
       12. The printing unit of  claim 1 , wherein said composite plastic is a structural plastic. 
     
     
       13. The printing unit of  claim 1 , wherein said composite plastic includes a component having a rubber-like character with high elasticity. 
     
     
       14. The printing unit of  claim 1 , wherein said at least one sliding surface has a sliding surface area of between 20 and 1,000 cm 2 . 
     
     
       15. The printing unit of  claim 14 , wherein said at least one sliding surface has a sliding surface area of between 40 and 400 cm 2 . 
     
     
       16. The printing unit of  claim 15 , wherein said at least one sliding surface has a sliding surface area of 100 cm 2 ±50%. 
     
     
       17. The printing unit of  claim 1 , wherein said movable side frame part has first and second spacing side frame halves that are opposite to each other and that at least one sliding surface is secured on each of said first and second side frame halves. 
     
     
       18. The printing unit of  claim 1 , wherein each said movable side frame part has at least two of said sliding surfaces spaced apart from each other. 
     
     
       19. The printing unit of  claim 1 , wherein said plurality of depressions are ones of grooves and flutes. 
     
     
       20. The printing unit of  claim 1 , wherein said plurality of depressions cover said sliding surface in the form of a net. 
     
     
       21. The printing unit of  claim 2 , wherein said displaceably mounted side frame part has an undersurface and further wherein said at least one sliding block is positioned on said undersurface. 
     
     
       22. The printing unit of  claim 2 , further including at least two of said sliding blocks assigned to each said movable side frame part. 
     
     
       23. The printing unit of  claim 20 , wherein there are three of said sliding blocks on each said movable side frame part. 
     
     
       24. The printing unit of  claim 1 , wherein said displaceably moveable side frame part has an undersurface and further wherein said three sliding blocks are positioned on said undersurface. 
     
     
       25. The printing unit of  claim 1 , wherein said plurality of depressions occupy a surface ratio of more than 10% of said at least one sliding surface. 
     
     
       26. The printing unit of  claim 25 , wherein said plurality of depressions occupy a surface ratio of more than 20% of said at least one sliding surface. 
     
     
       27. The printing unit of  claim 26 , wherein said plurality of depressions occupy a surface ratio of between 25% and 35% of said at least one sliding surface. 
     
     
       28. The printing unit of  claim 27 , wherein said plurality of depressions occupy a surface ratio of 30%±3% of said at least one sliding surface. 
     
     
       29. The printing unit of  claim 1 , including a base for said printing unit and having spaced lateral supports and further including guide rails on said spaced lateral supports, said at least one sliding surface contacting said guide rails. 
     
     
       30. The printing unit of  claim 29 , further including at least one guide roller support having guide rollers mounted on said guide roller support for rotation about a vertical guide roller axis of rotation, with at least one guide roller support laterally guiding said at least one displaceable side frame part on said guide rails. 
     
     
       31. The printing unit of  claim 30 , wherein said guide rollers are arranged on first and second sides of said guide rail. 
     
     
       32. The printing unit of  claim 1 , wherein there is one first side frame part and one second side frame part. 
     
     
       33. The printing unit of  claim 1 , wherein one of said at least first and second side frame parts is stationary. 
     
     
       34. The printing unit of  claim 33 , wherein one of said side frame parts is displaceable with respect to said one stationary side frame part. 
     
     
       35. The printing unit of  claim 1 , wherein said printing unit is a printing tower. 
     
     
       36. The printing unit of  claim 1 , further including a plurality of said printing couples mounted one above the other in said printing unit. 
     
     
       37. The printing unit of  claim 36 , wherein said plurality of said printing couples are blanket-to-blanket printing couples including transfer cylinders. 
     
     
       38. The printing unit of  claim 37 , wherein said printing unit is separable along a plane of contact of said transfer cylinders on each of said blanket-to-blanket printing couples. 
     
     
       39. The printing unit of  claim 1 , further including at least four of said printing couples arranged one above the other in each side frame part. 
     
     
       40. The printing unit of  claim 1 , wherein each printing unit is a printing tower with four blanket-to-blanket printing units arranged one above the other and further wherein one of said side frame parts is stationary and another of said side frame parts is movable. 
     
     
       41. A printing unit comprising:
 at least a first side frame part and a second side frame part, a spacing distance between said first side frame part and said second side frame part, relative to each other, being adjustable in a horizontal direction of displacement by movement of at least one of said first side frame part and said second side frame part, relative to the other of said at least first side frame part and said second side frame part in said horizontal direction of displacement: 
 at least one of a printing couple and a part of a printing couple accommodated on each of said first and second side frame parts; 
 a mounting supporting said movable one of said at least first and second side frame parts for movement in said direction of displacement between a closed functional position, in which said first and second side frame parts are moved together and are fixed relative to each other, and an open position in which said at least first and second side frame parts are spaced from one another in said direction of displacement; 
 at least one sliding surface in said mounting and supporting said movable one of said at least first and second side frame parts, said at least one sliding surface being a composite plastic comprised of multiple materials: and 
 a plurality of depressions in said at least one sliding surface, said plurality of depressions extending in a longitudinal direction at an angle with respect to said direction, of displacement and being capable of holding soil. 
 
     
     
       42. The printing unit of  claim 41 , wherein said displaceable side frame part is movable in a said direction of displacement and further whereon said sliding surface has a grid of intersecting ones of grooves and flutes forming said plurality of depressions. 
     
     
       43. The printing unit of  claim 41 , wherein said plurality of depressions form an angle of 45′ with respect to said direction of displacement.